Motor control apparatus



March 22, 1932. B. E. OHAGAN 1,850,893

MOTOR CONTROL APPARATUS Original Filed July 5-, 1929 l F I Cm i (Q w H E INVENTOR I ,6,E.O q7nn, "fiZ/Q'EZJTLM Mina/65M Patented Mar. 22 1932 UNrrsD-srTas swrrorr & sIG-NAL ooNrPA Y, or PENNSYLVANIA Application filed Jul 5,1929, Serial My invention relates to motor control apparatus. I

I will describe two forms of apparatus embodying my inventiomiand will then point out the novel features thereofin cla1ms.

In the accompanying.drawings, Fig. 1 1s a diagrammatic view showing oneform of apparatus embodyingmy invention applied to a control of a motor for operating a railway:

simiway switch A through the medium of suit able operating mechanism forming no part of my invention and therefore not shown n the drawings, but it will be readily understood that the motor M might be used to control any other suitable form of apparatus.

Associated with the motor M is'a motor controller G comprising two contactors E and'F. The contactor E, in the form here shown, comprises a. magnetizable armature 38 pivoted at 38 and controlled by a 'wmdmg 36. The armature 38 is operatively connected with two contacts at and 9.. When winding 36 ,is de-energized, the armature38 occupies the position in which it is illustrated in the drawings and the contacts 4 and 9 are open. VJ hen winding36 is energized, however, the armature 38 is rotated in a clockwisedirection to a position in which the contacts stand 9 are closed. In similarmanner, the contactor F comprises a magnetizable armature 39 pivoted at 39 and controlled by a winding 29.

The armature 39 is operativ-ely connected.

with two contacts 16 and19. When winding 29 is ole-energized the armature 39 occupies the po'sition'shown and contacts 16 and 19 are open; but, when winding 29 1s energized. armature 39 is rotated ina counter-clockwise direction to a position inwhich the contacts TENT O F BERNARD n. oI-IAGAN, or swIssv Lrr PENNSYLVANIA, AssIcNoR :10 THE UNION I;

svv ssvALn, PENNSYLVANIA, A CORPORATION or Moron CONTROL Arr'ARA'rUs 110,376,046. Renewed ma 12,'-'19s1.

abutments'tl and 42, and is arranged to coact with the armatures 38 and 39 of the contactors E and F in such manner that. one armature cannot be moved to'the position in which its associated contacts are closed unless the other armature occupies the position-in which its associated contacts are open, thus insuring that the contacts-of both contactors cannot be simultaneously closed.

The motor controller C alsocomprises two thermo-sensiti've relays and T. The thermo-sensitive relay S comprises a thermo-sensitive device whichchanges its shape in response tochanges in its temperature, and a heatin'gtelement 21- for heating the, device. As here shown, the thermo-sensitive device is abi-metallic str'ipfl27 arranged in such manner that the free end ofthe strip will de flect upwardly when :the heating element 21 is supplied with current, the magnitude of which exceeds the magnitude of the normal operating current for motor M. The bimetallic strip 27 operates a contact 2727*' which isnormally closed but which becomes opened when the strip 27 is deflected. Asso ciated with the strip 27 is a pivoted latch 43, provided with a notch 453 and biased to the position shown by means of a spring 44; The

upperend of the latch 43 is connected by a wire 46 orother suitable link with the upper end of the'armature 38 of contactor E. The parts or relay S are-so arrangedand proportioned that when the strip'27 is'deflected upwardly, the end of the strip '27 will be engaged by thelatch 43 at the notch 43*? and held in the deflected position until winding 36 of contactor ,E' is subsequently energized, at which time the movement of the armature 38. of contactor E to its energized position swings the link in a clockwise directionagainst the bias of the springee and releases the strip 27-.

The thermo-sensitiverelay T is similar to the thermo-sensitive relay S and comprisesa bi-' metallic strip 34 arranged to deflect upwardly when a heating element ll associated with the strip issupplied with current the magniture of which is greater than themagnitude;

ofthenormal operating current formotor M. The strip 34 operates a'contact34 -3e3 andco-operates with a pivoted'latch e9,w hich 10o 2727 and 3434 are closed.

is provided with a notch 49, and which is biased to the position shown by a spring 47. The upper end of the latch 49 is connected by a wire or other suitable link with the upper end of the armature 39 of contactor F, and the parts are so arranged and so proportioned that when the bi-metallic strip is deflected upwardly the end of the strip will enter the notch 49 and will be held in the deflected position until winding '29 of contactor F is energized to rotate the latch to a position in which the latch is out of engagement with the bimetallic strip 34.

The motor controller C may be controlled in any suitable manner. As here shown it is controlled by a circuit controller D operativelyconnected with the switch A, and by a po larized relay R. The circuit controller 1) comprises a contact arm 31 which coacts with two contact segments 31 and 81 The parts of the circuit controller D are so proportioned that the arm 31 will engage the segment 81 to close the contact 3131- at all times except when the switch occupies its e21 treme normal position in which it is illnstrated in the drawing, and that the arm 31 will engage the segment 31 to close contact 3131 at all times except when the switch A occupies its extreme reverse position. The polarized relay R, in turn, may be controlled in any suitable manner, as by pole-changin contacts on a switch lever located in the train dispatchers office.

As'shown in the drawings, switch A 00- cupies its normal position so that contact til--31 of circuit controller D is closed and contact 3181 is open. Polarized relay R is energized in its normal direction. Contactors E and F are both de-energized and contacts 9 and 4 of contactor E and contacts 16 and 19 of contactor F are therefore open. Motor M is deenergized. Bi-m'etalli'c strips 27 and 34 of thermal relays S and T both occupy their normal positions in which contacts I will now assume that the train dispatcher wishes to reverse switch A. To do this he reverses the polarity of the current supplied to relay It so that relay It becomes energized in the re verse direction to open normal contact 25-25 and close reverse contact 2525 Currrent is then supplied to win-ding 36 of contactor E from the terminals B and X-of a suitable source of current not shown in the drawings overa'circuit which passes from terminal B of the source through wire 23, front contact 24 of relay R, wire 24 reverse contact 2525 of relay R, wire '33, contact 34-34 of th'ermo-sens'itive relay T, wire 35, winding 36 of contactor E, wire 37, contact 31-31 of circuit controller 1) and wire to terminal X. As a result, winding 36 of contactor E becomesenergized, and armature 38 is linoved to the position in which contacts 9 and 4 of the 'contactor are closed. When these contacts are closed, a circuit for motor M is completed, and current flows from terminal B ofthe source through wire 3, contact 4 of contactor E, wires 5 and 6, armature 1 of motor M, wires 7 and 8, contact 9 of contactor E, wire 10, heating element 11 of relay T, wires 12 and 13, field winding 2 of motor M, and wire 14 to terminal X. Motor M therefore operates to move switch A from its normal to its reverse position. When the switch reaches its full reverse position, contact 3l31 of circuit controller D opens, thereby interrupting the circuit previously traced for winding 86 of contactor E, so that contactor E becomes ole-energized and opens its contacts 4 and 9. When contacts 4 and 9 of contactor E are opened, the circuit just traced for motor M is interrupted and the motor stops. All parts are then deenergized.

If, after the switch has reached its full reverse position, the train dispatcher wishes to restore the switch to its normal position, he restores relay R to its normal position, in which it is illustrated in the drawings. Contact 3131 of circuit controller D is now closed, and current therefore flows from terminal B of the source through wire a3, neutral contact 24 of relay R, wire :24, normal contact 2525 of relay R, wire 26, contact 2727 of relay S, wire 28, winding 29 of contactor F, wire 30, contact 3131 of circuit controller D, and wire 32 to battery X. Contactor F therefore becomes energized and closes its contacts 16 and 19. When these contacts are closed, a circuit is completed for motor M from terminal B of the source through wire 15, contact 16 of contactor F, wires 1? and 7, armature 1 of motor M, wires 6 and 18, contact 19 of contactor F, wire 20, heating element 21 of relay S, wires and 13, field winding 20f motor M, and wire 14 to terminal Motor M then operates to re store switch A to the normal position. When the switch reaches its full normal position, contact 3131- of circuit controller D opens and (Lie-energizes contactor n hen contactor F becomes de energized, the contactor opens its contacts and interrupts the circuit just traced for motor M so that the motor stops, and the parts are then restored to the positions in which they are illustrated in the drawings.

if the motor current rises above the normal Value for any reason when switch his being moved from one extreme position to the other, the motor will be automatically de-energized, so that damage to the motor is prevented. For example, I will assume that the motor current rises above the normal value when switch A is being moved from its normal to its reverse position due to the move ment of the switch being arrested by some obstruction before the switch reaches its full reverse position. As pointed out hereinbe fore, when switch A is being moved from its normal to its reverse position, motor M is energized over the contacts 9 and 4 of'cont'actor' V E, and heating element'll .o ffrelayiT is in cluded in the motor circuitflilt'will be apparent, therefore, that when the'motorI'current rises above the normal valuevunder the above conditions, bi-metallic strip "34 of v lay T becomes heated, and the end of the strip deflects upwardly and is engaged to the latch 49. The circuit for contactor E Y is then opened at contact 3434 of relay T so that contactor E becomes de-energized and thus tie-energizes motor T/l.

After motor M has been defenergized 1n 3 this manner, the motor cannot again be energized in the direction to move switch-A toward its reverse position untilstrip 34 is released and returns to its normal position in which contact 3434 "is closed If the train dispatcher now energizes relay R in the normal direction so that its contact 2525 becomes closed, contactor F will become energized and will rotatelatch 49' out of engagement withstrip 34. If strip 34 has had time to cool before this is done,

toward its initial or normal position, and

when switch A reaches its normal position, contactor F automatically becomes dc-encrgized at contact 31-31 of circuit controller D." Latch 49 then returns to the normal [3081* tion towhichit is biased by the spring 47, and

if strip 34 is still heated, the latch will rethe strip and will hold the strip in its deflected position until the latch is manually operated to rele'asethe strip.

IIl'S111'l1lEll manner, it the motor current rises above the normal value when switch A- is being moved from its reverse to itsnor mal position, strip 27 of relay S will become h deflected and will degenergi-ze contactor F,

thereby de-euergizing motor M. 'When strip 27 becomes deflected, latch 43 engages the strip and holds the strip in its deflected po sition.

released and returns to itsnormal position 1n wh1ch contact 274 27 is closed. "If relay R is energized in the reverse direction'so that its-contact 2525 becomes closed, contactor E will become energized and will rotate latch 43 out of engagement with strip 27. 7 If strip 27 has cooled before this is done, the strip will immediately return to its normal position and close contact 272' If bimetallic 7 strip 27 is still heated, however, when this Motor M cannot then again be 611+ erglzed 1n the dlrection tomove switchgA toward'its normal POSltlOIlllIltll strip 27 is done,-l'atc h 43 may re-eng'age'the strip 27 1atch 43 is manually rotated out of engagement with the strip.

Referring now to the modified form of.

apparatus illustrated in Fig. 2, I have here shown, associated with bimetallic strip 34 of thermo-sensitive relay T a latch 51'having two notches 51: and. 51, The latch 51 is pivoted at 51 and is biased to theposition shown by] the spring 47. The notch 51 in the latch 51 coacts with the bimetallic strip 34 in the same manneras the notch'49 in the latch 49 :coacts with the strip 34 in Fig. '1; The notch 51 :coacts" with a lock rod 53 pivotally attached near its upper end to a pivoted arm-54 which is biased to an upper position by a spring 55. The lower end of the lock rod 53'is provided with an elongated slot 53 which receives a pin 48 attached to the bimetallic strip 34. The upperportion of the latch 51 is connected with the armature 39 of contactor F by the wire 50 in such manner that,.when contactor F is energized, the latch is rotated in a counter-cloclnvise direction to a position in which the latch. is out of engagement with'the strip 34. The

:and the strip cannot then beireleased'unless parts are so proportionedthat when bimetallic strip 34 is undefiected,thepin 48 engages thelock rod '53 at thebottom of the slot 53*, and holds the 'lock'rod out of the notch 51.

in the latch 51 but that when strip 34 is deflected, the upper-end ofthe rod enters the vnotch 51 in latch 51, if contactor' F. is. en-

ergized. I a i V With the apparatus constructed in this manner,the operation of the apparatus when switch A is being moved from one extreme position to the other under normal conditions is the same as described in connection with Fig.1. "If the motor currentrises above the normal value when switch A-is being,

moved from its normal to its reverse position,

ho'wever,"the operationofthe apparatus is When the motor current rises above the normal value, bimetallic strip 34 of relay T becomes deflected and opens con as follows:

tact 34'34 -of relay T, thereby de-energiz- 'ing contactor E, and hence dc-energizing moto'r'M. l/Vhen strip 34 becomes deflected, the end of the strip enters notch 51 in latch 51 and isengaged by the latch so that the strip is subsequently held in its deflected position. If relay R is now energized in the reverse direction, to energize contactor F, latch 51 -'Will be'rotated out of engagement with strip 34.} If strip 34 has cooled before this is done, 1 the strip will immediately return toits normal position and close contact"3434 of relay T; If strip 34 is still heated, however,

when latch 51 is rotated out of engagement with strip 34, the spring 55, acting through the'arm54, will cause the lock rod53 to enter,

the notch 51". When the lock rod 53 enters the notch 51 in the latch 51;,--it ho1ds the latch out of engagement with strip 345 until strip 8% cools even though contactor F becomes de-energized. lVhen strip 34: cools, the pin 48 engages the rod 53 "at the bottom of the slot 53 and automatically pulls the lock rod 53 out of engagement with the latch, whereupon the latch returns to its normal position. lVhen bimetallic strip 3-1 of relay T has returned to its normal position, contact $434 of relay T becomes closed and. the motor may then again be energized in the direction to move the switch from its normal to its reverse position by energizing'relay R in the proper direction as will be readily understood from an inspection of the drawings.

If desired, relay S may also be provided with latching apparatus similar to that shown in Fig. 2 in connection with relay T.

One advantage of the apparatusshown in Fig. 2 over that shown in Fig. 1, is that when a thermalrelay has operated due to eX- cessive current in the motor circuit, it is unnecessary to wait until the bimetallic strip of the relay has cooled before reversing relay R to release the strip.

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a movable device, a first and a second winding, a motor for driving said device, means effective when said first winding is energized for supplying said motor with current to operate said motor in one direction, a normally closed contact arranged to be opened it the current supplied to said motor exceeds a predetermined value when said first winding is energized, a latch. eitective when said contact is opened for subsequently holding said contact open, means for releasing said latch when said second winding is energized, and manually controlled means tor at times energizing said first winding over said contact and for at other times energizing said second winding.

2. In combination, a device capable of assuming a first or a second position, a motor for operating said device, a first and a second winding, a first normally closed contact arranged to be opened if the current supplied to said motor exceeds a predetermined value when said first winding is energized, a second normally closed contact arranged to be opened it the current supplied to said motor exceeds a predetermined value when said second winding is energized, means eiiective when said first contact is opened for holding said first contact open until said second winding is subsequently energized, means efiectivc when said second contact is opened for holding said second contact open until said first winding is subsequently energized, and manually controlled means for at times energizing said first winding over said first contact and for at other times energizing said second winding over said second contact.

3. In combination, a movable device, a first and a second winding, a motor for driving said device; a thermo-sensitive relay comprising a bimetallic strip which becomes deflected when heated, a heating element for heating said strip, and a contact controlled by said strip; means including said heating element for supplying said motor with current when said first winding is energized to operate said motor in one direction, means effective when said strip is deflected for subsequently holding said strip in its deflected position until said second winding is energized, and manually controlled means for at times energizing said first winding over said contact and for at other times energizing said second winding.

4. In combination, a device capable of assuming a first or a second position, an electric motor for operating said device, a first and a second winding; a first thermo-sensitive relay comprising a first heating element, a first bimetallic strip arranged to become deflected if said first heating element is supplied with current the magnitude of which exceeds a predetermined value, and a first contact which is opened when said first strip is defiected; a second thermo-sensitive relay comprising a second heating element, a second bimetallic strip arranged to become deflected if said second heating element is supplied with current the magnitude of which exceeds a predetermined value, and a second contact which is opened when said second strip is deflected; means effective when said first winding is energized and including said first heating element for supplying said motor with current to move said device from said first position to said second position, means effective when said'second winding is energized and including said second heating element for supplying said motor with current to move said device from said second position to said first position, means effective when said first strip is deflected for holding said first strip in its deflected position until said second winding is energized, means efiective when said second strip is deflected for holding said second strip in its deflected position until said first winding is'energized, and manually controlled means for at times energizingsaid firstwinding over said first contact and for at other times energizing said second winding over said second contact.

5. In combination, a device capable of assuming a first or a second position, an electrio motor for operating said device; a first contactor comprising a first winding, a first armature controlled by said first winding,

which becomes deflected when heateda first heating element for heating said firststrlp,

and a first and a second contact controlled by said first armature; avsecond contactor com prising a second winding, a second armature controlled by said second winding, and a third and a fourth contact controlled by said secondarmature; means assoclated with said first secon d armature for preventing either armature from moving to the position where its associated contacts are closed unless the other armature'occupies a position where its associatedcontacts are open, means controlled by said first and secondcontacts for supplying said motor with current to drive said device from said first position to said second position, means controlled by said third and fourth contactsfor supplying said motor with current to drive said device from said second position to said first position, a fifthnormally closed contact arranged to be opened it the current supplied'to said motor exceeds a predetermined value when said first and second contacts are'closed, a sixth normally closed contact arranged to be opened it the current supplied to said motor exceeds a predetermined value-when saidthird and fourth contacts are'closed, and manually controlled'means for at times energizing said first winding over said fifthcontact and for at other times energizing said'second winding over said sixth contact. I

6. In combination, a device capable ofas-- suming a first or a second position, an'elec-' tric motor for operating said device,-a' first and a second winding, afirst thermojsensltiverelay comprising a first bnn'etalllcstrip Vanda first contact controlled by said'first strip; a second thermo-sensitive relay comprising a second bimetallic strip which becomes deflected when heated, a second'heating element for heating said second strip, and

asecoud contact controlled by -said 'second strip; means controlled by said first winding and including said first heating element for supplying said motor with current todrive said derice fr'om said first position to I said second position, means controlled by said SGCOIlClWlRClZIJg and lncluding sald second heating element for supplyingsaidm tor with current to drive said devlce from said second position to said. first position,

means including said first contact for at times energizin aid first winding, fmeans 1nclud-.

ing said second'contacttor at other times energizing sald second Winding, a first latch controlled by said second wlnding and biased to one position in such manner that said first latch will engage said first strlp'when said first-strip becomes deflected? and subsequently hold said first. strip in its deflected posi tion until said second winding is subsequently energized, and a second latch controlled by said fi st winding and biased to one position in such manner that said secondlatch :said second winding for moving said'latclr will engage said secondstrip when saidsecond strip becomes deflected and subsequently hold said second strip in its deflected position until said firstWinding' is subsequently trolledbysaidfirst Winding and includingsaid first heating element for supplying said motor with'current to drive said device from said first position to said'second position, means controlled by said second winding and including said second heating element for supplying said motor with current V to drive said devicefrom said' second 'position to saidfirst position, a firstbimetallic strip controlled by-said first. heating element in such manner that saidfirst strip becomes deflected -if said first heating element is supplied with: current having a magnitude which'exceeds'a predetermined value, asecond bime tallic strip controlled by said second heating e0 element I in V such.- mann'er that said-secondstrip'becomesdefiected ifsaid second heating element is supplied with current having a} magnitude: whichexceeds a predetermined; value, a firstcontact'controlled by said firsti fib imetallic strip, a second contact controlled by said second bimetallic strip means' associated with saidfi'rst strip and" controlled by said second'winding for at times holding said I first strip in its deflected position, means associated with, said second strip'and con; trolled bysaid first winding for at otheri times holding said secondstrip in its deflect ed position, a circuit for said-first windingin-' eluding said first contact, and a circuit for 105, said second winding mcludmg saldsecond deflected when heated, a heatingelement fort heating said strip, anda' contact controlled-- by said'strip; meansicontrolled by said first winding and including said heating element g for supplying said motor with current to1 drive said devicefrom said first position to r 7 said second position, means controlledby saidsecond 'winding'ffor supplyingsaid motorwith current to drive said device fromsaid-z second position to said first position, 'ma-nually-controlled means including said conf tactforat times energizing said first wind ing, manuallycontrolled means for at other @1 times energizing said "second, winding,t a f' v a latch arrangedvto engage saidstrip when said j strip becomes deflected" to hold said strip in; its deflected position, means'controlled-by out of engagement with said strip, and means connected with said strip for holding said latch out of engagement with said strip until said strip cools if said latch is'moved out of engagement with said strip when said strip is heated.

9. In combination, a railway switch having normal and reverse positions, an electric motor operatively connected with said switch, a first and a second winding, a first and a second heating element, means controlled by said first winding and including said first heating element for supplying said motor with current to drive said switch from its reverse position to its normal position, means controlled by said second winding and including said second heating element for supplying said motor with current to drive said switch from its normal position to its reverse position, a first bimetallic strip controlled by said first heating'element in such manner that said first strip becomes deflected if said first heating element is supplied with current having a magnitude which exceeds a predetermined value, a second bimetallic strip controlled by said second heating element in such manner that said second strip becomes deflected if said second heating element is supplied with current havinga magnitude which exceeds a predetermined value, a first contact controlled by said first bimetallic strip, a second contact controlled by said second bimetallic strip, a circuit controller controlled by said switch andhaving a fourth contact which is closed at all times except when said switch occupies its normal position and a fifth contact which is closed at all times except when said switch occupies its reverse position, a circuit for said first winding includ ng said first contact and said fifth contact, a circuit for said second winding including said second contact and said fourth contact, a first latch controlled by said second winding and biased to one position in such manner that said first latch will engage said first strip when said first strip becomes deflected and subsequently hold said first strip in its deflectedposition until said tactor comprising a first winding, a first armature controlled by said first winding, and contacts controlled by saidfirst armature; a second contactor comprising a second windond Winding, and contacts controlled by said second armature; a first thermo-sensitive relay comprising a first bimetallic strip which becomes deflected when heated, a first heating element for heating said first strip, and a first contact controlled by said first strip; a second therm-o-sensitive relay comprising a second bimetallic strip which be comes deflected when heated, a second element for heating said second strip, and a second contact controlled by said second strip; means controlled by the contacts of said first contactor and including said first heating element for supplying said motor with current to drive said switch from its normal position to its reverse position, means controlled by the contacts of said second contactor and including said second heating element for supplying said motor with current to drive said switch from its "reverse position to its normal position, a circuit controller provided with a third contact which is closed at all times except when said switch occupies its extreme reverse position and with a fourth contact which is closed at all times except when said switch occupies its extreme normal position, a manually controlled polarized relay having a fifth contact which is closed when said polarized relay is energized by current of one relative polarity and'a sixth contact which is closed when said polarized relay is energized by current of the other relative polarity a circuit for said first winding including said sixth contact, said first contact, and said third contact; a circuit for said second winding including said fifth contact, said sec-ond contact,'and said fourth contact; a first latch controlled by said second armature and biased to one position in such manner tha said first'latch will engage said first strip when said first strip becomes deflected and subsequently hold said first strip in its deflected position until said second winding is'energized; and a' second latch controlled by said first armature and biased to one position in such manner that said second latch will engage said second strip when said second strip becomes deflected and subsequently hold said second strip in its defiected position until said first winding'is energized.

1.1.In combination, a movable device, a first and a second winding, a motor for driving said device, means effective when said first winding is energized for supplying said motor with current to operate said motor in one direction, a normally closed contact arranged to be opened if the current supplied to said motor exceeds a predetermined value when said first winding is energized, means effective when said contact is opened for subsequently holding said contact open until said second winding is energized, and manually controlled means for at times energizing, said first winding over said contact and second winding.

ranged to be opened it the current supplied to said motor exceeds a predetermined value when said first winding is energized, mech-' anism effective when said contact is opened for subsequently holding said contact open, means operating upon theenergization of said second winding to render said mechanism ineffective, and manually controlled means for at times energizing said first wind 'ing over said. contact and for at other times energizing said second winding.

13. In combination, a movable device, a first and a second winding, a motor for dr1v-- ing said device, means efiective 'when'saidfirst winding is energized for supplying said motor with current'to operate said motor-in device is arrested when said first windingis" energized, means effective when said contact is opened for subsequently holding said contact open until said second, winding is energized, and manually controlled means for at times energizing said first Winding over said contact and for at other times energizing said 14. In combination, an electric motor, a winding, means controlled by said winding when said winding is energized fo r supplying said motor with current to operate said mo- -tor in one direction, governing means operatlng if the currentsupplied to said motor when said winding is energized exceeds a predetermined. value i'or governing said wmding, other means efiective when said governing means has operated for subsequently retaining said governing means in the operated condition, and manually controlled means for at times energizing said winding and for at other times releasing said governing means from the operated condit1on.

15. In combination, an electric motor a first and a second. winding, means controlled by said. first winding when and only when said first winding is energized for supplying said motor with current to operate said motor in one direction, other means operating it the current supplied to said motor when said first winding is energized exceeds a predetermined value for modifying the control of said means by said first winding, means efi ective when said other means has operated for subsequently retaining said otliermeans in the operated condition until said second winding is energized, and manually controlled means for at times energizing said first winding and for at other times energizing said second windin 16. In comblnatlon', an electric m0tor,'a

first and a second winding, means controlled by said first winding when said first winding is energized for supplying said motor with current to operate said motor in one direction, a contact arranged to be operated if the current supplied to said motor exceeds a predetermined value when said first winding is energized for controlling said first winding, means effective when said contact has been operated for subsequently holding said contact in the operated position until said second winding is energized, and manuallycontrolled means for at times energizing said first winding and for at other times energizing said second winding.

117. In combination, an electric motor, a first and a second winding, means controlled by said first winding when said first winding is energized for supplying saidmotor with current to operate said motor in one direction, a contact arranged to be operated if the current supplied to said motor exceeds a predetermined value when said first winding is energized for controlling said first winding,

mechanism effective when said contact has been operated for subsequently holding said contact in'the operated position, means operating upon the energization of said second winding to render said mechanism ineffective, and manually controlled means for at times energizing said first winding and for at other times energizing said second winding.

18.'In combination, a movable device, a motor for driving said device, 'a first and a second winding, means controlled by said first winding when and only when said first winding is energized for supplying said motor with current to operate said motor in one direction, other means operating if the motion of said device is arrested when sa1d first winding is energized formodifying the con trol of said means by said first winding, means efiectlve when sa1d other means has been operated for subsequently retalning said other means in the operated condition first winding'when said first winding is energized for supplying said motor with current to operate said motor in one direction, a con tact arranged to be operated if the motion of said device is arrested when sa1d first winding is energized for controlling said first winding, means efiective when said contact ally controlled means for at times energizing said first winding and for at other times energizing said second winding.

20. In combination, an electric motor, a first and a second winding, a normal circuit controlled by said first winding for supplying said motor with current when and only when said first winding is energized, a reverse circuit controlled by said second winding for supplying said motor with current when and only when said second winding is energized, means associated with said first and second windings for preventing the supply of current to both said normal and said reverse circuits simultaneously, means associated with each of said normal and said reverse circuits and responsive to the magnitude of the current supplied to said motor for modifying the control of said normal and said reverse circuits by said first and said second windings respectively, and manual 1y controlled means for at times energizing said first winding and for at other times energizing said second winding.

21. In combination, an electric motor, a first and a second winding, a normal circuit controlled by said first winding for supplying said motor with current when and only when said first winding is energized, a reverse circuit controlled by said second winding for supplying said motor with current when and only when said second winding is energized, means associated with said first and second windings for preventing the supply of current to both said normal and said reverse circuits simultaneously, first and second means associated respectively with said normal and said reverse circuits for modifying the control of said normal and said rei' fl'verse circuits by said first and said second windings and arranged to be operated when the current supplied to said motor exceeds a predetermined value, means efiective when said first means has been operated for subsequently retaining said first means in the operated condition until said second winding is energized, means efiective when said second means has been operated for subsequently retaining said second means in the operated 'condition until said first winding is energized, and manually controlled means for at times energizing said first winding and for at other times energizing said second winding. 22. In combination, an electric motor, a

first and a second winding; a thermo-sensitive relay comprising a bimetallic strip which becomes deflected when heated, a heating element for heating said strip, and a contact controlled by said strip; means controlled by said first winding and including said heating element for supplying said motor with current to operate said motor in one direction when said first winding is energized, means controlled by said second winding for supplying said motor with current to operate said motor in the other direction when said second winding is energized, manually controlled means for at times energizing said first winding over said contact and for at other times energizing said second winding, retaining means for holding said strip in the deflected position, means controlled by said second winding for releasing said strip from the deflected position, and means controlled by said strip for rendering said retaining means ineffective it said second winding is energized before said strip has become cooled.

23. In combination, a device capable of assuming a first or a second position, an electric motor for operating said device, a first and a second winding; 21 thermo-sensitive relay comprising a bimetallic strip and becomes deflected when heated, a heating element for heating said strip, and a contact controlled by said strip; means controlled by said first winding and including said heating element for supplying said motor with current to drive said device from said first position to said second position, means controlled by said second winding for supplying said motor with current to drive said device from said second position to said first position, manually controlled means including said contact for times energizing said first winding, manually controlled means for at other times energizing said second winding, a latch provided with a first and a second notch and biased to one position in such manner that when said strip becomes heated said strip will be engaged by said latch at said first notch and held in its deflected position until said latch is moved out of engagement with said strip, means controlled by said second winding for moving said latch out of engagement with said strip, and a push rod biased to one position and pivotally attached to said strip in such man nor that if said latch is moved out of engagement with said strip when said strip is deflected said rod will enter said second notch and hold said latch out of engagement with said strip until said strip cools:

24. In combination, a railway switch having normal and reverse positions, an electric motor operatively connected with said switch, a first and a second winding, a first and a second heating element, means controlled by said first winding and including said first heating element for supplying said motor with current in such manner that said motor moves said switch from its normal position to its reverse position, means controlled by said second winding and including said second heating element for supplying said motor with current in such manner that said motor moves said switch from its reverse position to its normal position, a first bimetallic strip controlled by said first heating elementin such manner that said first strip becomes deflected if said first heating element is supto engage said first strip when said strip becomes deflected, means for causing sald secplied with current the magnitude of which it exceeds a predetermined value, a second bimetallic strip controlled by sald second heating element in such manner-that said second strip becomes deflected if said second heating element is supplied with current the magnitude of which exceeds a predetermined value, a firstcontact controlled by said first bimetallic strip, a second contact controlled by said second bimetallic strip, a circuit controller controlled bysaid switch and having a third contact which is closed at all times except when said switch occupies its normal position and a fourth contact which is closed at all times except when said switch occupies its reverse position, a circuit for said first winding including said first contact and said fourth contact, acircuit for said'second wind- .7 ing including said second contact and said third contact, a first latch associated with said first strip, a second-latch associated with said second strip, means for causing said first latch ond latch to engage said second strip when said second strip becomes deflected, means controlledjby said first winding for causing said second latch to be moved out of engagement with said secondstrip, means controlled by said second winding for causing'said first.

latch to be moved out of engagement with said first strip, means controlled by said first strip for holding said first latchout of engagement with said first strip until said strip 7 returns to its normal position if said latch V is moved out of" engagement with the strip when the strip is deflected, and means con- 7 trolled by said second strip for holding said second latch out of engagement with said' second strip until said second strip returns to its normal position if said second latchis moved out of engagement with the strip when the strip is deflected.

In testimony whereof I afiix my signature. BERNARD E. OI-IAGAN. 

